Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
  • G03B21/00—Projectors or projection-type viewers; Accessories therefor
  • G03B21/132—Overhead projectors, i.e. capable of projecting hand-writing or drawing during action
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/26—Printing on other surfaces than ordinary paper
  • B41M1/30—Printing on other surfaces than ordinary paper on organic plastics, horn or similar materials
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
  • Y10T428/24835—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] including developable image or soluble portion in coating or impregnation [e.g., safety paper, etc.]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31855—Of addition polymer from unsaturated monomers
  • Y10T428/3188—Next to cellulosic
  • Y10T428/31884—Regenerated or modified cellulose
  • Y10T428/31891—Where addition polymer is an ester or halide

Definitions

• Clear plastic films are generally used as image carriers for the overhead projection.
• the information to be conveyed in the form of written or graphic representations are applied to the film as black or colored markings using a writing or drawing device.
• the overhead projector is normally used as a daylight projector, i.e. H; used in non-darkened rooms. Therefore, the markings on the film must be particularly legible. It was previously thought that black or colored writing on a white background was legible, but it has been shown that this legibility can be significantly improved if a color contrast is added to the brightness contrast, i. that is, if the light and dark (black / white-en) parts of the display do not have the same color and are different from black / white.
• indicator systems have the crucial disadvantage that they respond to manual welding, that is, the acid contained in the andsch procedure H leads to a reaction and therefore (yellow) to fingerprints on the slide. This significantly reduces the value of these known systems. Added to this is the lack of lightfastness of the indicator dyes. The markings will fade if the foils are used again frequently.
• the present invention has for its object to provide O verhead films on which you can generate a light font on a dark background, especially a yellow font on a blue background, which is lightfast and insensitive to hand perspiration.
• this goal is achieved in two ways.
• a reducible blue dye as a blue component, which can be made colorless with a sulfite-containing solution.
• the yellow font is created by the reducible blue color mixed a non-reducible yellow dye or dyes the film yellow before applying the blue dye or adds a yellow dye to the sulfite solution.
• a color reaction system as is also used for color reaction papers.
• a color former such as crystal violet lactone is developed to a blue color with a developer substance such as bisphenol and applied to a film.
• Such color reactions are erased, for example, with polar liquids such as glycols.
• the yellow writing is achieved either by admixing a permanent yellow dye to the color reaction system or by coloring the film or by adding a yellow dye to the extinguishing liquid.
• the coatings of the films with reducible dyes are preferably carried out from an aqueous binder-containing solution, polyvinyl alcohol or another transparent drying binder or a dispersion being used as the binder.
• an adhesive layer made of polyvinyl acetate can be applied beforehand, in which case the contrasting yellow dye can already be added to this layer.
• the contrasting yellow dye must be added to the coating composition in a ratio of 1: 5 to 1:10 (yellow: blue).
• the vote The ratio of yellow: blue, which can also be larger or smaller than 1: 5 to 1:10, depends on the dyes used (reddish yellow, greenish yellow) and on subjective aesthetic considerations.
• All dyes which can be colored with reducing substances can be used as reducible dyes, in particular those which are used for producing erasable inks, e.g. B. ink blue, astrazon violet etc.
• reducible dyes e.g. B. ink blue, astrazon violet etc.
• the selection of the irreducible contrast dyes is only limited by the solubility of the same in the chosen coating composition.
• Such foils can be written on with commercially available ink eraser pens.
• the film is coated with color reaction systems from coating compositions containing organic extinguishing agents.
• An adhesive layer is usually not necessary.
• the coating compositions contain a contrast dye which is stable against polar solvents in those cases in which no colored adhesive layer or a colored film or an eraser pen containing the yellow dye is used.
• solvent-soluble dyes can be used as permanent contrast components, all of which are known to be stable against polar solvents such as glycols or glycerol.
• polar solvents such as glycols or glycerol.
• Such foils are described with pens that contain glycerin, glycols or other polar solvents.
• the coating weights of the colored layers on the overhead film are preferably between 0.5 and 6 g / m 2.
• the thickness of the adhesive layer is preferably between 0.1 and 0.5 g / m2.
• a correction of the markings generated is possible both in the reduction process and in the color reaction process.
• a pen which contains a dilute acid such as acetic acid
• a pen which contains bisphenol dissolved in a solvent.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Heat Sensitive Colour Forming Recording (AREA)
• Illuminated Signs And Luminous Advertising (AREA)
• Laminated Bodies (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

Country Status (4)

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Citations (6)

Family Cites Families (1)

• 1979
  • 1979-03-26 DE DE2911798A patent/DE2911798C2/de not_active Expired
• 1980
  • 1980-03-12 EP EP80101261A patent/EP0016407B1/fr not_active Expired
  • 1980-03-12 AT AT80101261T patent/ATE5161T1/de not_active IP Right Cessation
  • 1980-04-01 US US06/136,397 patent/US4296150A/en not_active Expired - Lifetime

Patent Citations (6)

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